Arrangement in dismountable office swivel chairs



Dec. 23, 1958 F. FOLKNER ARRANGEMENT IN DISMOUNTABLE OFFICE SWIVELCHAIRS Filed Jan. 22, 195'? V T [02 IN EN 0R ARRANGEMENT IN DISMOUNTABLEOFFICE SWIVEL CHAIRS Frithjof Falkner, Oslo, Norway Application January22, 1957, Serial No. 635,224

Claims. (Cl. 15595) The present invention relates to a swivel chair andhas for its object to provide such a chair which can be dismantledeasily and quickly into a number of separate parts capable of beingstowed or re-packed in such a manner as to occupy a minimum of space,for transport or storage purposes, but which can also be re-assembledquickly and easily by unskilled persons.

Another object of the invention is to provide a chair having the abovecharacteristics which is of the kind comprising a spider supportedsleeve and a seat provided with a central journalling shaft, theconnection between said seat and the spider supported sleeve beingresilient and adjustable in height and such that said seat is alsorotatable in relation to the spider. Such chair is further preferablyprovided with an adjustable back rest and arm rests also. In the chairaccording to the invention a spider provided with a central journallingsleeve for a 'pivot shaft secured to the seat contains a spring deviceand a height adjustment device constructed as a separate closed unit,which when dismantled permits the seat and the spider to be stored witha minimum occupation of space by arranging the seat pivot in thejournalling sleeve of the spider.

The invention will be better understood from the following descriptionof one particular embodiment, by way of example, with reference to theaccompanying drawings, wherein:

Figure l is a side view of a swivel chair according to the invention,

Figure 2 is a similar view with the parts separated,

Figure 3 is a side view showing the seat and the spider in stowedposition, and

Figure 4 is a cross section on an enlarged scale through the springingand height adjusting means which also constitutes the means forpermitting rotation of the seat in the horizontal plane.

The chair in the illustrated embodiment comprises a seat 1 which issecured to supporting cross bearers 2 and 3 of suitable sheet materialextending from front to back and laterally, respectively. Securedsubstantially centrally between the cross-bearers 2 and 3 is adownwardly extending tubular seat pivot 8. By means of a part shown inFigure 4 the pivot 8 is connected with a spider 14, which is providedwith a central journalling sleeve 9 and preferably mounted on casters asshown.

The chair is provided in a conventional manner with an adjustable backrest 6, 7 and arm rests 4.

The cross-bearers 2, 3 are substantially U-shaped in cross-section andprovided with an oval cavity, as clearly shown in Figure 2 with respectto the laterally extending cross-bearer 3. This cavity of thecross-bearer 3 may be narrowed by means of a screw so that the lower end5 of the arm rest 4, which is bent laterally inward, may be introducedin the cavity and will be held tightly so as securely to support the armrest. By loosening of said screw it is possible easily to pull out thearm rest and thereby separate it from the seat. The back rest attain)Patented Earn 23, 1958 .port in known manner.

The connection between the seat 1 and the spider 14 comprises anintermediate unit shown on an enlarged scale in Figure 4. This unitconsists of a sleeve 10 closed at its lower end by a plug 10a. At theopposite end of the sleeve 10 is secured a downwardly extending externalarm 11 which at its upper end is: welded to the sleeve 10 and near itslower end is provided with a locking pin 12 projecting into the spacebetween the inside of the arm and the outer surface of the sleeve 10.The locking pin may be pulled out by means of a knob 12a against theaction of a spring 1212 located in a spring housing 12c.

A helical spring 19 is arranged inside the sleeve 10 and said springabuts at one end against the plug 10a in the lower end of sleeve 10 andat its other end engages a disc 17 mounted at the upper end of a pin 18extending between the convolutions of spring 19. The pin 18 is somewhatshorter than the spring 19 in its expanded state and thus serves as ameans for restricting the compression of the spring, so that the lattercannot be fractured by being overloaded. The upper surface of the disci7 is provided with a spherical recess in which is placed a steel ball20, and resting on ball 20 is a corresponding disc 16 with a similarrecess. An upwardly projecting spindle 15 extends from the disc 16. Astop pin 21 projects into the interior of sleeve ill above disc 16 andprevents the parts located in the sleeve llil from being removedtherefrom. When the parts are assembled the tubelike seat pivot 8 isintroduced in the sleeve 19, and the spindle l5 enters the inner cavityof the pivot ii. The spindle 15 is at its upper end] provided with meansfor causing it to engage frictionally in the upper end of the tubularpivot a. This can be achieved by making the spindle l5 tubular also, andslotting the upper end as illustrated at 15' in Figure 4, the upper endof the tubular pivot 8 then being constructed correspondingly to providea convenient friction securing means between the upper ends of thespindle i5 and pivot 8 so that the chair may be lifted by the seatwithout the lower parts falling out under their own weight.

The lower end of the sleeve 10 is adapted to be placed in the sleeve 9,secured to the spider 14, whereupon the locking pin 12 is selectivelyengaged in one of a series of vertically spaced apertures 13 in thesleeve 9 according to the desired adjusted height for the chair.

When the parts of the chair are dismantled the seat 1 and the spider 14may be stowed in the manner shown in Figure 3, wherein the seat isinverted with the pivot it being directed upwards and the spider 14 isarranged on the seat in such a way that the pivot 3 extends up wardiyinto the sleeve 9, as shown. Thus, the seat and spider may be stowed ina manner which gives a minimum height, and the other parts, that is, thesleeve It), the armrests 4 and the back rest 6, 7 may be stowed aroundthe main parts, whereby the entire dismantled chair may be packed in arelatively small space.

In addition to providing for the convenient separation and assembling ofthe parts of the chair as above described, the described chair has ajournalling arrangement embodied in the sleeve 10 which providesadvantages over the previously known devices. The fact that thespringing, rotation and height adjustment are effected by elementsassembled in a closed separable unit has the advantage that oil orgrease can come into contact with the person who uses the chair. Thelower part of the sleeve it is preferably filled with grease so that theparts of the chair are effectively lubricated. Besides providing a chairwhich is convenient for transport and storage, the invention alsoprovides a chair which, in

sembling ,of these parts .canbe c maimedtdhdinengfmb ide s a simpleheight adjustrnent andgives' a pleasant springing, while at the sametime, the rotation of the seat about a vertical axis can be r t a d, aafan ra l i-t-t Ihssha r ma be and wi or'without arm rests if desiredsine he removal; ndasd out in;a rsirnple Way The connection between thebaclt rest 6 and-,the

back ,support itself may a lso vbeicarried o ut in any lgnoyvn,r'nanner, whereby a ,guick separation and assembling -o f jtlre partscan be simply achieved.

I'iflaim-IK I "f 1 Q2131 i 1 A ,ivel chair comprising a seathavinga-piyot therein oin, a. spider haying a eentral,

jvertica l ly, j extend F WE-91 99 verticahpo sition -of said devicerelative to said sleeye, the inner diarne" 1* offlsa id sleeve being atleast as large lastlteputerd ameter of saii d pivot shaft .so that, when,said'height adjustment device i s;removed fr orn said,sleeveandseparatedf from said-shaft, said seat can be disposed invertedposition below said spiderwith said shaft, entendinglupwardly into, said,sleeve for storage in alre latively small space; said height adjustmentdevice ineluding atubnlar member whieh is closed at its lower end and,dimensioned to, extend slidably into said sleeve, a .helical springinsaid tubular m ember and resting on said lowenend of t hella tter,rotatable means supported by saidspring, andaspindle carried by saidrotatable means and projecting upwardly from said tubular member, saidpivot shaft beingwhollow and opening downwardly to telescope into saidtubular member around said spindle. 2. A, swivel, chair as in claim 1;further comprising means for preventing withdrawal of-said-spindle from,said. tubular member, and frictionally engageable means for holdingsaid spindle in said hollow pivot shaft so that the chair can be liftedby its seat without inadvertently geparating sa idshajt from aidheightadiustmentdevice.

3. A swivel chair as in claim 1; wherein said rotatable means includeslower and upper discs resting on said spring and secured to saidspindle,'respectively, said discs having central, spherical recesses inthe confronting faces thereof, and a ball bearing between said discs andlocated in said recesses. 1

4..A swivel chair as in elaim 3;,furtherw-comprising a pin dependingfrom saidtlowerwdisc' and surrounded by said helical spring, said pinhaving a length substantially less than the. length of: said helicalspring in the unstressed conditionof the latter,..said.pin.being,adapted to engage said lower end of the tubular member for preventingoverloading of ;said; spring;;.

5. A swivel chair as in claim 1; wherein said sleeve has a series ofvertically spaced apart openings therein, and said releasablecooperating means for adjustably determining .the vertical positionofsaid device relative -totsaid sleeveincludesan arm extending verticallyat =the outside. ofsaid tubular member and secured to the latter:onlyadjacent its upper end,- said arm being spaced-radiallyqfrom said,tubular'member along asubstantial portion ofthe, length of .the...armto=extend ,downwardly at the outside of saidsleeve Whenvsaid tubularmember is slidably nreceivedin. said sleeve, and a -locking pincarriedby, said v:arrnand springlurged inthe direction' toward said. tubulanmember to enter a selected one of said series of openings in saidsleeve.

